The objective of this research proposal is to transform antigen-specific B lymphocytes and to use the transformed B cells lines to study at the biochemical level the processes of lymphocyte induction and paralysis. Transformation of enriched populations of antigen-specific lymphocytes will be obtained by somatic cell hybridization with B lymphoma cell lines and by viral transformation. The cell lines to be used as parents in the hybridization experiments include Abelson virus-transformed lymphomas as well as chemically-transformed B lymphomas expressing surface immunoglobulin. The viruses to be used are Abelson leukemia virus, the Duplan isolate of the radiation leukemia virus, SV40, Avian sarcoma virus and MC29. The SV40 and avian sarcoma viruses to be used are temperature-sensitive for transformation and will allow the study of clones exhibiting a normal phenotype at the non-permissive temperature. The selection of a temperature-sensitive Abelson leukemia virus is proposed. The transformed B lymphocyte lines will be used to study induction and paralysis in an in vitro immune response system. The finding that these lines are activated by antigen and accessory cells will provide for the analysis of soluble factors released by the accessory cells which generate the induction signal and for the study of the accompanying induction.